Textile finishing



United States Patent 3,102,042 TEXTILE FINISHING Alexander F. Gortvai,Utica, N .Y., and Emile J. Monfils,

New Bedford, Mass., assignors to United Merchants and Manufacturers,Inc, New York, N.Y., a corporation of Delaware No Drawing. Filed Sept.2, 1958, Ser. No. 758,587

3 Claims. (Cl. 117-7) This invention relates to the treatment of textilefabrics in the piece, and more particularly, to the finishing ofcellulosic fabrics, that israyon, sometimes called regeneratedcellulose, and especially to fabrics made up of or containing asubstantial portion of continuous filament rayon as distinguished fromfabrics made solely from spun rayon, and fabrics having a substantialportion of spun rayon therein.

One purpose and object of the present invention is to impart aglass-like appearance to filament rayon fabrics.

A further object is the production of textile finishes for filamentrayon fabrics which thereby acquire certain so-called non-iron orno-iron properties; that is to say, it is a purpose and object of theinvention to produce fabrics and finish the same, which will not requireany ironing after laundering.

Further objects of the present invention are to provide textile finishesfor filament rayon fabrics, or fabrics containing a substantialproportion of filament rayon, which will be characterized by having aresidual shrinkage of not substantially more than l /z% in both warp andfilling, even after repeated laundering or washing.

A still further object is a method of treating fabrics which will notresult in any substantial diminution of tensile strength by reason ofthe finishing process. A further object is a process for impartingspecial properties and effects to filament rayon Woven or knit-tedfabrics which will be characterized by an adequate, or more thanadequate, resistance to abrasion.

Another object is a method and means of applying a new type of finish tofabrics of the character referred to above, which will be therebyrendered wholly or substantially resistant to household bleaching.

A still further object is to produce a permanent finish in filamentrayon fabrics, that is to say, a finish which will withstand repeatedwashing of the fabric.

Other and further objects will appear hereinafter.

According to the present invention, it has been found that by applying alarge amount of a low polymer urea formaldehyde resin impregnatingsolution to a bright viscose rayon woven or knitted fabric of 300 denieror more, and incorporating in the impregnating solution a metalliccatalyst, namely, zinc nitrate, in an amount substantially in excess ofthe theoretical amount required to obtain fully substituted tertiarynitrogen, and subsequently washing the finished or treated goods toremove free formaldehyde and excess catalyst, a fabric thus impregnatedexhibits the properties above specified and differs from conventionalfabrics of like character in its ability to be laundered, dried, andreturned to service without any need of ironing, and its further abilityto retain this characteristic after an indefinite number of launderings;such fabric being further characterized in that although the finishedgoods will retain chlorine after chlorine bleaching, they are notsubsequently weakened or discolored on exposure to light or heat.

Apparently, the properties above described are obtainable by theapplication of such finish or impregnating agents only with respect toknitted or woven goods of bright filament rayon (viscose rayon) having adenier of 300 or larger, although the weave of such fabric may be 3,l@Z,MZ Patented Aug. 27, 1963 2 of any style, such as leno, basket,novelty, or jacquered weave.

Further, according to the present invention, the goods are first scouredby any conventional method or means, and dried on dry cans or tenterframe so as to retain 3% to 6% moisture, which is to say, the goods mustnot be bone dry.

Enough resin for a single days run must be made fresh and used within a24 hour period. The resin is made up as follows:

Dissolve 120 lbs. of urea in 480 lbs. of 37% formaldehyde. Adjust the pHto 8.2 with sodium dicarbonate. Raise the temperature to F. and allowthe reaction to proceed for one hour. Temperature will rise to F. to F.Cool with ice; dissolve 30 lbs. of zinc nitrate in the mix; add 40 lbs.of Meltone RH softener (Crown Chemical Co.), and adjust the volume to100 gallons. pH should now be 6.0 to 6.3.

The prepared goods are run through this solution in a conventionaltwo-bowl pad with a pressure of 15 tons. They are then pre-dried on fourdrying cans at F. They then go into a 90 foot tenter frame withtemperatures of 305 F. at the entering end, and 325 F. at the dischargeend. The entire process is run at 45 y.p.m.

The goods are finally washed in 25% Na CO and .05 synthetic detergent at160 F. for 10 minutes, rinsed and dried.

The product or fabric finish thus obtained may be used for a variety ofend purposes such as curtains, draperies, bedspreads, Slipcovers, orwearing apparel, and is characterized by the fact that it requires noironing after laundering, and will drip dry; that it has adequate tensilstrength and resistance to abrasion for the end use selected; that it isnot damaged or discolored by chlorine bleaching, or any residualchlorine which may be left in the goods after laundering; that it has aresidual shrinkage of not more than l /2% either warpwise orfillingwise, even after repeated laundering; and such fabric retains allof these characteristics even after 10 or more launderings.

As heretofore indicated, the special effects or properties obtained bymeans of the finish above described can only be obtained on or inknitted or woven fabrim constituted of bright viscose rayon of 300denier or larger. In applying the resin or impregnating agent to fabricsof that character, care must be taken that the resin is a low polymerresin alkaline precondensate, and after making up the same, the resinshould be used within 24 hours after its manufacture. Use of the termlow polymer is intended to indicate a resin which is theoretically 100%monomeric, but in practice it has been found to be some thing less thanthat, to wit, approximately 95% monomeric and 5% polymeric. It is alsoimportant that the precondensate resin or urea formaldehyde solutionshould be alkaline in nature, and not an acid solution. By adjusting thepH to 8.2 with sodium bicarbonate the alkalinity of the solution isassured. The reason for using the resin finishing solution within aperiod of about 24 hours after its manufacture is because if it is keptmuch longer than that, undue polymerization will result; and if theresin, thus further polymerized, is subsequently applied to the cloth,the fabric will be unduly tenderized or otherwise damaged.

In practice it has been found that the amount or con centration of theurea formaldehyde resin in the treating or finishing solution should besubstantially about 21% by weight of the treating or finishing solution.If the urea formaldehyde concentration is substantially less than 21% byweight, the desired properties and improvements in the fabric are notobtained. If substantially more than 21% by weight urea formaldehydeconcentration is employed in the finishing solution, the fabric isdamaged. Thus it may be said that a by weight urea formaldehydeconcentration of about 21% of the impregnating or treating solution isof rather critical importance.

With respect to the catalyst employed in the present impregnatingsolution, it has been found that there is no substitute for the metalliccatalyst above specified, namely, zinc nitrate, and it has been furtherfound that this specific catalyst should be incorporated in the treatingsolution in an amount within the range of from about 3% to about 5% byweight of the treating solution. The preferred and desired quantity ofconcentration of the catalyst is 4% by weight of the treating solution.

A typical resin impregnating solution formulation is as While a varietyof softeners may be used as additives to the formulation, such softenersmust be non-chlorine retentive. It is also to be mentioned that thegoods should be dried before finishing, to the point where they retainnot substantially more or less than from about 3% to 6% moisture. In anyevent they should not be bone dry. After finishing, the goods should bewashed to remove excess unreacted formaldehyde and catalyst.

Thus, in carrying out the present invention, a specific fabric, that is,woven or knitted bright viscose filament rayon of at least 300 denier,is given a special resin finish by applying thereto, in the mannerdescribed above, a finishing composition comprising about 21% by weightconcentration of low polymer urea formaldehyde resin in the form of analkaline precondensate and metallic catalyst, namely, zinc nitrate, inan amount of concentration within the range of from about 3% to about5%, and preferably in a concentration of 4% by weight of the treatingsolution; and following the application of the treating solution to suchfabric the goods are cured, washed, rinsed, and dried. As a result ofthis treatment there is imparted to such fabric a special finish wherebythe fabric achieves a glass-like appearance, which is to say, itvisually appears to be a heavy fabric with a glossy finish, in theserespects resembling fabrics made from fiberglass. Such fabric, thustreated, will drip dry and does not require any ironing afterlaundering. It is further characterized by resistance to abrasion,resistance to bleaching, absence of substantial residual shrinkage, andpermanency of finish.

In the light of the foregoing, the following is claimed:

1. Bright viscose rayon fabric of at least 300 denier impregnated with aresin treating solution comprising about 21% by weight of ureaformaldehyde low polymer resin and zinc nitrate as a catalyst in aconcentration of from about 3% to about 5% by Weight of the treatingsolution.

2. Low polymer urea formaldehyde finishing composition for 300 denierbright viscose rayon woven and knitted fabrics comprising an alkalineprecondensate including urea formaldehyde in a concentration of aboutsubstantially 21% by weight of the treating composition, and a metalliccatalyst, namely, zinc nitrate, in a concentration of from about 3% toabout 5% of the treating composition.

3. Method of applying a permanent finish comprising a glass-likeappearance to bright viscose rayon woven and knitted fabrics having adenier of at least 300, which comprises the steps of running suchfabrics through a treating solution comprising about 21% by weightconcentration of urea formaldehyde, and from about 3% to about 5% byweight concentration of zinc nitrate, squeez- :ing the goods thustreated to remove excess treating solution, and subsequently drying thetreated goods at a temperature of about F. and passing the dried goodsthrough a te-nter frame heated to temperatures within about 305 F. to325 F. at a speed of about 45 yards per minute, and finally washing thetreated, dried, and tentered goods at about 160 F. for about 10 minutes.

References Cited in the file of this patent UNITED STATES PATENTS2,219,375 Widmer et al. Oct. 29, 1940 2,267,276 Hager Dec. 23, 19412,622,995 Lippert et a1. Dec. 23, 1952 2,653,921 Sulzer Sept. 29, 19532,846,337 Cooke et a1. Aug. 5, 1958 2,911,326 Haney et al Nov. 3, 1959

3. METHOD OF APPLYING A PERMANENT FINISH COMPRISING GLASS-LIKEAPPEARANCE TO BRIGHT VISCOSE RAYON WOVEN AND KNITTED FABRICS HAVING ADENIER OF AT LEAST 300, WHICH COMPRISING THE STEPS OF RUNNING SUCHFABRICS THROUGH A TREATING SOLUTION COMPRISING ABOUT 21% BY WEIGHTCONCENTRATED OF UREA FORMALDEHYDE, AND FROM ABOUT 3% TO ABOUT 5% BYWEIGHT CONCENTRATED OF ZINC NITRATE, SQUEEZING THE GOODS THUS TREATED TOREMOVE EXCESS TREATING SOLUTION, AND SUBSQUENTLY DRYING THE TREATEDGOODS AT A TEMPERATURE OF ABOUT 160*F. AND PASSING THE DRIED GOODSTHROUGH A TENTER FRAME HEATED TO TEMPERATURES WITHIN ABOUT 305*F. TO325*F. AT A SPEED OF ABOUT 45 YARDS PER MINUTE, AND FINALLY WASHING THETREATED, DRIED, AND TENTERED GOODS AT ABOUT 160*F. FOR ABOUT 10 MINUTES.